I have fitted a new ECU and it has cured the coolant warning light problem and the temp gauge is now working and has claered all fault codes.
However one of the original problems was that the engine would not idle, when I checked the supply to the idle control valve there was 12v to both circuits at the plug with KOEO, surely this is not correct. With the new ECU it is the same, I have also aquired a new idle valve as it appears that the one fitted was inncorrect. I am reluctant to plug in the new valve until I can verify that the supply to it is correct. I have checked the wiring back to the ECU for short to ground and spurious voltage, non found. TPS shows .5v closed and 4.8 fully open, lambda is good, as is intake air temp. I have a wiring diagram for Marrelli 4. but this is for fly by wire which has no stepper motor idle valve, The vehicle in question is an early incarnation with a throttle cable. Does this need adaptation when fixed, Any help much appreciated, Regards, Neil.